Oxygen Administration
| Parent skills |
Medical Patient Assessment for Chest Pain (OPQRST) Medical Patient Assessment for Respiratory Distress (PASTE) |
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| Self-assessment | |
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Be familiar with indications and cautions associated with providing Oxygen Therapy Review the following skills for safely administering Oxygen in the field | |
| What links here | |
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Drug Administration Safety Checks (the 5 rights) Medical Patient Assessment for Chest Pain (OPQRST) Medical Patient Assessment for Respiratory Distress (PASTE) Primary Assessment | |
Oxygen therapy is an essential tool in the prehospital environment as it can help the patient maintain tissue oxygenation and essential life functions while minimizing cardiopulmonary work. The primary indication for oxygen therapy is hypoxemia (decreased level of oxygen in the blood) which can be measured with a pulse oximeter (see pulse oximetry in the Vitals section). Oxygen therapy, which raises the percentage oxygen from 21% (room air) to as much as 100% (non-rebreather mask on high flow) greatly increases the efficiency of the patient's breathing.
The decision to start Oxygen therapy is often made during your primary assessment (ABCs) based on clinical signs such as:
- Tachypnea or low respiratory rate which can both be clinical signs of hypoxia
- Cyanosis and/or delayed capillary refill
- Respiratory distress, labored breathing and anxiety.
- Oxygen saturation under 90% by pulse oximetry.
For the patient to maintain adequate oxygen levels in the blood and delivery of that oxygen to the tissues, the entire respiratory chain must be intact. An interruption or interference in any of these steps can result in hypoxia (inadequate perfusion of the tissues). It is helpful to understand where in the respiratory chain the patient's difficulty is coming from, as it can guide additional therapies or trigger rapid transport.
| "Broken link" in the respiratory chain | Pathology | Clinical signs | Additional therapies for the EMT to consider |
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| Airway obstruction (upper or lower) | Foreign body obstruction, Severe allergic reactions, Airway swelling or damage from trauma, Asthma, Bronchitis, and COPD can all significantly impede airflow into the lungs | Airway narrowing often produces a variety of adventitious (abnormal) sounds. Listen for wheezing and stridor | Suction, bronchodilators, epinephrine, and airway adjuncts to address cause of the obstruction |
| Overwhelming Work of Respiration.
The contractions of the diaphragm and intercostal muscles must be strong enough to expand the lungs |
Pulmonary fibrosis or other pathologies that stiffen the lungs, and patient exhaustion from work of breathing can both result in inadequate expansion. | Look for signs the patient is using accessory muscles to breathe, has low chest rise, or appears exhausted. In children, respiratory arrest can quickly lead to cardiac arrest. | Assisted ventilations |
| Inadequate tidal volume (air per breath) | Pneumothorax or hemothorax decouples the lung from the chest wall so that the lungs do not fully expand with the intake of breath | Look for signs of injury to the chest wall, tracheal deviation and listen for faint or absent breath sounds | Assisted ventilations |
| Inadequate minute ventilation (average volume of breath per minute) | Stroke, drug overdose and other central nervous system issues can depress respiratory drive. | Respiratory rates (Breaths per Minute) that are too low indicators of inadequate breathing:
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Assisted ventilations |
| Impaired gas exchange. The alveoli must be open enough and have adequate surface area allow air in for gas exchange | Pneumonia, congestive heart failure can both fill the alveoli with fluid, preventing gas exchange and emphysema or other COPDs can lead to "dead air trapping" in lungs | Auscultate for "crackles" and diminished breath sounds at the base of the lungs indicating fluid build up | CPAP |
| Diminished Pulmonary Blood Flow. The lungs must have adequate blood flow through the capillaries to allow gas exchange with the blood | Pulmonary Emboli can block large portions of the lung vasculature preventing blood flow to that portion of the heart, and right sided heart failure can result in insufficient pulmonary blood pressure to get adequate perfusion | Patients can report pain with breathing, and show profound hypoxia with otherwise clear airways and adequate tidal volume | Rapid Transport |
| Inadequate oxygen carrying capacity. The blood must have enough active hemoglobin to transfer oxygen from the lungs to the tissues | Carbon monoxide or cyanide poisoning can occupy hemoglobin sites and prevent oxygen binding, and in anemia there are simply too few binding sites because the blood is dilute | Headaches, extreme fatigue, cherry red lips (cyanide) and skin pallor despite brisk capillary refill. Often will have "normal" SpO2 readings. Anemia may be caused in the field by volume resuscitation after significant blood loss | Removal from environment where poisoning may have occurred |
| Hypotension. There must be enough blood pressure to get oxygenated blood to all the tissues. | Acute heart failure, excessive blood loss or any source of hypovolemic shock can prevent otherwise oxygenated blood from reaching the body's tissues | Lightheadedness, dizziness, pale, diaphoretic, slow capillary refill | IV Volume replacement |
Cautions/Contraindications
Care should be taken with patients with chronic hypercapnic conditions. Their values for oxygen saturation can be as low as 80%, and supplemental oxygen can interfere with respiratory drive - you should be prepared to transition to assisted ventilation in these patients if necessary.
Equipment
Supplemental oxygen can be delivered via:
- Low Flow - Nasal cannula
- High Flow - Non rebreather Mask
- In conjunction with assisted ventilations - Bag valve mask
- As part of a CPAP (continuous positive airway pressure) system.